Method and apparatus for electroplating



Dec. 15, 1925- Filed Nov. 12 1923 Patented Dec. 15, 1925.

UNITED STATES,

PATENT OFFICE.

JOSEPH G. SWAIN, OF AKRON, OHIO, ASSIGNOR TO THE FIRESTONE STEEL PRODUCTS COMPANY, OF AKRON, OHIO, A CORPORATION OF OHIO.

I METHOD AND APPARATUS FOR ELECTROPLATING.

Application filed November 12, 1923. Serial No. 674,119.

I '0 all whom it 'r/iag concern:

Be it known that I, Josnrn G. SWAIN, a citizen of the United States, and a resident of Akron, county of Summit, State of Ohio, have invented certain-new and useful Improvements in Methods and Apparatus for Electroplating, of which the following is a specification.

This invention relates to a process of electroplating by which a coating of mercury or an admixture of mercury is obtained with the other metal deposited upon iron or steel objects. The process and apparatus are particularly designed to be used in conjunction with zinc plating or electrogalvanizing on metal automobile rims or similar objects.

In the drawings:

Figure 1 is a longitudinal section of a portion of a plating tank;

Figure 2 is a section thereof on the line 2-2 of Figure 3;

Figure 3 is a longitudinal section through one of the anodes used in the process; and Figure 4 is a section onathe line 44 of Figure 3. I

The process of the invention consists in applying to the metal article to be plated, in conjunction with the zinc plating, a suitable roportion of mercury. In the preferred operation of the rocess, this action is performed in a stri e tank, or as a preliminary step in the electroplating process, the usual coating or electroplating with zinc taking place after the strike coat is a plied. The process is performed by ano es of metallic mercury in conjunction with the zinc anodesfthe electric current bein passed through both of said anodes so t at a small proportion of mercury is carried over and deposited on the articles. This operation preferably is performed in an electrolyte containing a cyanide solution. The number of mercurial anodes relative to the zinc anodes may be limited 5. The rims are connected by means of brushes 6 to a conductor rail 7 mounted over the tank. The electric current passes through a conductor rail 8 at the side of the tank and through anodes suspended within the solution to the rims and then out through the rail 7 as will be readily understood.

In the carrying out of the present invention two types of anodes are suspended within the electrolyte. The greater number of the anodes are zinc bars or rods 10 suspended from the rails 8, while at intervals the mercury anodes are provided.

These mercury anodes are indicated by the numeral 11 in Figures 1 and 2. Their construction is clearly described in Figures 3 and 4:. They comprise rods 12 of copper or other suitable conducting material which for the major part of their length are incased in an insulating sleeve or shell 13, preferably of hard rubber or glass. At the base of the rod is attached a hard rubher or glass bowl or cup 14., which is attached to the rod by means of an integral cross bar 15 extendlng transversely of the cup. The metallic mercury is contained in the cup and is coveredover by insulating.

sieve or screen 16, the apertures of which permit the dispersion of mercury into the electrolyte.

The operation of the invention will be readily understood by those skilled in the art, and is not necessarily limited to strict conformance with the showing and descri tion herein contained. Chan es and mo ifications may be made as will e understood, without departing from the spirit of the invention.

What I claim is: I

1. In a rocess of electroplating, the steps of subjecting the article to be electroplated .to an electrolyte charged simultaneously from anodes of zinc and metallic mercury. 2. In a process of electroplating, the steps of subjecting the article to be electroplated to a strike coat in an electrolyte char ed from anodes containing zinc and meta lic mercury.

3. In a process of electroplating, the steps of subjecting the article tobe plated to a cyanide electrolyte charged from anodes containing zinc and metallic mercury.

4. In a process of electroplating, the step of simultaneously charging the plating solution through metallic mercury and a second plating metal.

5. In a process of electroplating, the steps of submerging within the electrolyte a mass of metallic mercury and simultaneously passing an electric current through the mercury as an anode and also through an anode of metallic zinc.

6. In the process of electroplating ferreous objects with zinc, the step of obtaining a strike coat of mercury and zinc by subjecting metallic mercury within the bath to an electric current simultaneously with zinc as anodes and subsequently plating with zinc.

.- An apparatus for electroplating comprising a cup, means to suspend the cup within the electrolyte, and means for conducting current to, the interior of the cup.

8. An apparatus for electroplating comprising a tank, a cup within the tank adapted to contain metallic mercury, a conductor rod extending to and terminating within the cup, and an insulating covering for the conductor to prevent electric contact with the body of the electrolyte.

9. An apparatus for electroplating comprising a tank for holding electrolyte, a cup within the tank, a conductor rod, an insulating sleeve about the rod, and a perforated cover over the cup.

JOSEPH G. SWAIN. 

